Harbster is fairly changed from its pre-evolution, becoming bipedal in appearance the Pokémon adopts a Pirate aesthetic to its appearance having part of the carapace covering its back form a Tricorne on its head with its ears appearing from the area within the carapace. The Pokémon's muzzle remains unchanged although its chin is slightly lower down giving it a larger end to its snout than before. The carapace covering its back now appears to form somewhat of a jacket for the Pokémon protecting its chest and forming large plates around its side and back that have a net-like appearance for the Pokémon. It stands on its hind legs which are larger, longer and have large patches of carapace and fur covering the legs, its feet are slightly larger than before with the second toe being the largest of the four on each foot.
Its claw-like hands have changed significantly, one now has a completely claw-like appearance, when not gripped appearing like an Anchor with a side-grip acting as the central point of the anchor appearance. The other claw meanwhile has taken on a more armour-like appearance appearing like a gauntlet for the Pokémon with its paw visible beneath. The patch of fur on its chest is still present with the fur around its belly remaining present while the fur that would be covered by the chest carapace spills out from the top of the carapace forming what appears like a cravat on the Pokémon. Its tail remains split in four and protrudes well past its large carapace plates and has an armoured appearance of its own, the side tails are smaller than before and end in singular carapace spikes. The central two tails meanwhile appear more akin to a lobster tail appearing segmented and have a burst of fur at the end of each similar to the tail fin of lobsters.